Question

What is the reproduction stages(specify the species of parasites) in Ciliates , Amoeboid, Flagellates ​

Answer 1

• Ciliates reproduce asexually by division: the micro nucleus undergoes mitosis, while in most ciliates the macro nucleus simply pinches apart into two. This process is shown in the drawing above. However, ciliates also reproduce sexually, through a process known as conjugation. Conjugation is often induced by lack of food. Two ciliates of opposite mating types come close together and form a cytoplasmic bridge between the two cells; the micromuclei divide by meiosis, the macronuclei disintegrate, and the conjugating cells exchange haploid micronuclei over the cytoplasmic connection. They then separate, reform new macronuclei from their micronuclei, and divide. This may not sound very sexy, but remember that the essence of sexual reproduction is forming a new organism from the combined genetic material of parents. After conjugation, each ciliate partner has acquired new genetic material, and divides to give rise to progeny with a new combination of genes. This is essential to the survival of ciliate lineages; most ciliates cannot reproduce indefinitely by asexual fission, and eventually die out if prohibited from conjugating.
• Different species of amoebae reproduce differently. For example, some species produces spores as a means of reproduction. In the case of Amoeba proteus, it reproduces asexually through binary fission (A. proteus can be called “immortal”, as it does not die due to natural death on its own, due to binary fission). To prepare for reproduction, A. proteus starts with withdrawing its pseudopodia to make a more spherical shape. Mitosis occurs in the nucleus and the cytoplasm is pinched in the center of the original cell to form two (daughter) cells. The cell division results in two identical cells, or clones, because A. proteus reproduces asexually and so it simply copies its genetic information into the second cell. There is no genetic recombination nor crossing over of homologous chromosomes. The nucleus holds the key to survival and reproduction, as with many organisms. For example, if a segment of the amoeba was sliced off, producing two parts, the segment containing the nucleus would recover and continue to function normally, while the segment without (cytoplasm and possibly organelles) would shrivel up and die. The video below shows an animation of binary fission in amoebae.
• They reproduce by binary fission. They spend most of their existence moving or feeding. Many parasites that affect human health or economy are flagellates. Flagellates are the major consumers of primary and secondary production in aquatic ecosystems - consuming bacteria and other protists.